Lithium ion batteries have been receiving a demand for charging and discharging at high speed and longer lifetime. It has been known that speed of charging and discharging as well as adhesion can be improved by enhancing the adhesion with the active material and the like by providing a conductive resin layer on the conductive substrate of the lithium ion secondary battery.
For example, Patent Literature 1 discloses an under coat layer using chitosan. In addition, Patent Literature 2 discloses using nitrocellulose, polymethyl methacrylate and the like as a binder in the active material layer of the negative electrode. Further, Patent Literature 3 discloses using polyvinylbutyral for the conductive resin layer. In Patent Literature 4, color tone of a paste including an active material used for the negative electrode is evaluated by the absorption spectrum in the visible region. Further, in Patent Literature 5, particle diameter of a carbon microparticle is specified.